Process of refining petroleum products



PatentedV Oct. 2.3, 1934 1,577,631 4 p PROCESS oF REFINING'PETROLEUM PRODUCTS Emerson 1o, Higgins, if., Ws'jf ii iiel', Calif.;

` and Franklin T. Gardner; Tulsa", Okla);

. vNo Drawing. Application June 8,' 1931;@ v

4 j g Serial No. 54,3,004

The present invention relates toman improved process for the purification andrening of` ipetroleun products f suchV as gasoline, kerosene;-

" 5 Qne of the objects of the invention is to treat these products,` inthe liquid state; with a re`` agentA capable' ofv removing' therefromjor altering acid substances and sulphur compounds', andV to effect' this in a single stage of operation and inaL substantially continuous manner."` y

'Anotn' object of he invention isv to refine and purify such a petroleum productA as gaso-i linewhich may or may not have-been' subjected ttreatmentvwith acid`s`, such for example as" sulphuric acidi, by means oi a neutralizing but Water-insoluble reagent, While at the same4 time eiecting the removal' of sulphur corrpoiln'dsv from the gasoline or alteration of sulphur compounds-'inthe gasline.

StillA a further object of thei'nvention is to treat gasoline containing -free acid' andsulphurcompounds with magnesium" hydroxide,V pref-A erablv inthe fo'inof the mineral brucite,` and with sulphur',i whichE latter element` isdsslvedi in the g'asol'nejthat isl undergoing the treatment A- further object ofthev invention is tofeffectv ther alteration of sulphur' compounds, such as mercaptans, in petroleum products' by' reagentsr which Willfrn metallic mercaptides by reacting- Withthe said-mercaptans,and then treating said mercaptides with anelement oi"V the groupfcoml prising oxygen, sulphur, selenium, and Vte' l luriurn, whereby' thev metallic merca'ptide is "decomposed into a"nietalloiide,sulphide,l s elenidel or tellir ride,l with theconeo'nitantk formation of' thedi@` sulphide of the radical Which formed apait" of the mercaptan. j( u I In'its broadest aspects, 'the invention comprises treatingp'etroleum products such,`for example, as adistillate havingv aboilingpoint up' to as high as 600 Fl by passing'the same throughs; body of bruoite for the purpose of rernovingacidV bodies therefrom while' at'tlie saine time altering the sulphurl compoundslbontained in this' dise' tillate by the expedient of adding dissolved sul:v phur to thesame* before it passes", through the brucite, whereby the'sulpliur c'onipoinids'whichl are present in the distillateV in the form'of Inercaptan'sy are` converted intoV disulphides", so' as: torender" the sam'efn'ot Vonly neutralrbut Whatis lrnovvrfirl-thisart assweet toxdoctyorf.y This terrn'- is applied toipetroleum `products fand f ar-'I ticularly to gasoline and kerosene;l Which'fwilrn'ot' give apositivefreaction lwhen tested 1AWitlijsoliilii'ifnn petroleum technology." y

InA the; rening' of petroleum' products suchv as gasoline, kerosene', andjthe like, it' is ciuszt'c'afnary,v l H in order to remove unsaturated cmpndsand 6'0 resins ofv resin'forming materials therefrom;r to" treatthe same withv sulphuric acid' folloviedl b5' Washing inan attempt t'o remove Vas much cf the acid as possible.l However, the petroleum l productthustreatedf cannot be rendered com- 65 pletelyf neutral unless `means are employed to remove theiresidual' acidl contanedin the saine; This i's u'suallyaccompl'ished by' treating the,` said petroleum, product'with sodiumfhvdr'xide'or other alkali?- so'l'uble. in" Water.' Inf accordance' 70 with.: the prsent rlverltfl,-` hoitiet/"ei",'4 al." natural' mineral;4 narnelw.vb'rucite,y which isfrnagnesiur'ri hydroxideMg'KOHg' is employed. The gasoline orwthe'r` petroleum product" is" passed." through the brucite,` preferably in an u'pvvard direction, 751

doctor rest descritta standard teit' books' on 'tliefbi'u'cite4 beinginlgranular forni.

V,Irl-order to" effect' thev alteration" of` sulphur` compounds contained intliegasoline' or other' petroleum; product. treated', it has' been'1 foundaccordance' with Lthe present invention-that 50: the," alteration of these: sulphur compoundsca' be" brought? about' andl rendered certain b`y add'- ing. tt-solution f an'ele'ment oftrismphuf group tothegaso'line, the'rnost convenientonebeing i sulphurrase-1f;which` is somewhat sommein Sf gasolineandfcan hence bereadily' admix'd with the petroleum product'being treated; Thereaction" that Vtakes plaide betweenthe" sulphur corn# pounds? inf the gasoline; f the magnesium" hydro-x ide-andthe sulphur?is'sbstantiaHy as follwsz' 90 ZRSH-PMgWOH)2;(RSl2Mg-F2I-I2O,`v thev first compound formed beingmagnesiurn mercaptide. Thisv merc'aptide' reactsI with the free sulphur added ,to form magnesium sulphide" and the disulphide of the' radical R which had been com- 95' bined vvithj" ,the sulphur in thej .Inerc'aptan RSI-I'. (RSlzlVlg-i-SRl-TSST-R-I- Mgs The magnesiumk sulphide thus formed is substantially in'- soluble the petroleum product and .WillQhence beretainedonf-3the bructa. While the purified 100 pirolelmprodut Containing the disulpmde ,is discharged frornnhetrucite Column .neutrali swet t@ 1190.120?? .@frlsgwill n satisfactorily .nass cher reql iredlir/ispectiontests for commercially rharketfabf-geoliles; In carryi -(cljutlnt'hef processen atcornmercial scale, itNis advisable tonernplola number of tow-V @15S llldlvth brucitee .Qn Awith `,1r1fafgnesium .hrdrqxide"rifddiicefarufically: frgmbmcitenow ever, is cbrirnereauyavinbie at slow price and 110 is hence to be preferred for this purpose. The gasoline or other petroleum productl to be treated is permitted to pass upward through a column of water preferably contained in a reservoir in the tower immediately below the brucite and is then slowly percolated upward in this tower through the brucite, which is maintained upon a suitable foraminous retainer. At a point in advance of that where the gasoline or other petroleum product enters the brucite tower, there is fed into it a solution of sulphur in gasoline, which gasoline in itself is sweet to doctor. no part of the present invention, the amount of mercaptans contained inthe petroleum product to be treated is determined; and from the above mentioned reaction, the amount of sulphur required to be added is calculated. Y rThe sulphur solution is fed into the product to be treated by any standard means whereby its exacty amount may be-controlled; in other words, the sulphur solution is metered into the stream of petroleum product which is entering the brucite tower. An excess of sulphur should be avoided, as the same might possibly-in the absence of sufficient mercaptans-be carried forward with the gasoline or other petroleum product, thus rendering the material unsatisfactory rfor recognized commercial uses.

While sulphur has .been described as the specific material, it will, of course, be understood Ythat the other elements ofthe sulphur group, such as oxygen, selenium,`and tellurium or other materials possessing similar chemical properties, will react similarly, although the cost of selenium and tellurium at thepresent time probably render their use commercially inadvisable.A

The brucite, whichis magnesium hydroxide, isl insoluble iny water but is readily dissolved by acids, with the formation of the corresponding magnesium salts. phur compounds containing petroleum product come in contact with the brucite, there will be formed magnesium sulphate,- magnesium sulphide, or magnesium hydrosulphide, all oft which compoundsare soluble in water but insoluble in the petroleum product or gasoline beingtreated.v These products are hence deposited upon the brucite and after a period, depending entirely upon the `amount of impurities such as acids and sulphurl Acompounds in the gasoline, render the brucite ineffective; whereupon it becomes necessary to regenerate the same so that itmay again be used.r For. this-reason, itis advisable to havek a plurality of brucite towers into any or all ofwhich petroleum product may be directed, as the exigencies of operation require. For example, when the tower ofv brucite has lost its efcacy, it is cut out of service by shutting off the supply of gasoline thereto and forcing water intothe bottom of the tower slowly so as to force the gasoline or other petroleum product ahead of thewater, whereby it is all removed from the tower and-the tower lled with water instead. This operation is, of course, carefully watched so as to prevent water from mixing with the purified gasoline in the storage tanks which are connected with these purifying towers. When the brucite tower has been filled with water, it is preferable to start pumping more water through the tower while' discharging that already added, this further water being prefera'bly'liot, being heated either externally of the tower ror by means of the injection of steam.

By analytical methods, which form v Water will dissolve and wash o' the material deposited upon brucite, although the magnesium hydroxide itself its only soluble in acids. After the brucite has been regenerated in this manner, the water is drawn off and air or superheated steam blown through the brucite to blow out as much of the water as possible which may be adhering thereto.

The essential novelty in the process thus resides in the production of magnesium mercaptides from the mercaptans or organic hydrosulphides contained in the petroleum product, and the secondary reaction whereby the said mercaptides are converted into disulphides by means of an oxidizing or sulphidizing reaction, as shown in the hereinabove described reactions. Other means for introducing the sulphur may be employed, provided only that it may become dissolved in the product which is undergoing treatment; for instance, it would be considered an equivalent to take a definite quantity of petroleum product and directly to add thereto `the required amount of sulphur while agitating the petroleum product to cause the solution of the added element, whereafter the resultant sulphurtreated product ispassed upwardly through the brucite tower or towers. The sulphur may A,also be added in suitable amounts bypassing the gasoline to be treated in whole or any part there-4 of through a small column of elemental sulphur of suitable particle size, inserted in the system before vthe brucite column. y 4 y i,

No apparatus has been described in connection with the present invention, as it relates purely and simply to a process which it is desired to protect by Letters Patent and for which the fol` lowing .claims are made: i

1. The process of altering mercaptans in gasoline which comprises adding elemental sulphur thereto and passing the resulting sulphur solution through a mass of brucite. 4

f 2. The process of purifying a liquid organic hydrocarbon which consists in dissolving an element ofthe sulphur group in the same and passing the resulting solution through a mass of a magnesium compound soluble in acids.,

3. The process of purifying a liquid organic hydrocarbon which consists in dissolving an element of the sulphurgroup in the same and passing the resulting solution through a mass of magnesium hydroxide. l i

4. The process of purifying a liquid organic hydrocarbon which consists in dissolving an element of the sulphur group in the same and passing the resulting solution through a mass of brucite. l

A5. The process of purifying gasoline which comprises dissolving sulphur in purified gasoline, adding said solution to a'streamof impure gasoline that is to be purified, and passing the resultant mixture through a mass of granular brucite.

V6. The process of rendering a petroleum distillate sweet to doctor which comprises passing the same through a mass of sulphur, then through a body of water, and then through a mass of magnesium hydroxide. y

7. The process of rendering a vpetroleum distillate sweet to doctor which comprises-mixing the same with an element of the sulphur group and passing the resultant mixture successively through a body of water and a mass of magnesium hydroxide.

8. The process of rendering a petroleum distillate sweet to doctor which comprises mixing magnesium hydroxide and, while n contact with said hydroxide,V converting said mercaptides into the disulphides of the radical of said mercaptans by treatment with an oxidizing agent of the sulphur group.

11. The process of purifying petroleum products containing mercaptans so as to convert said mercaptans into organic disulphides which consists in treating said products with sulphur while passing through a mass of granulated magnesium hydroxide containing substantially no adsorbed water.

EMERSON C. HIGGINS, JR. FRANKLIN T. GARDNER. 

